Final answer:
The nurse should first begin infusion of 0.9% Sodium Chloride to address dehydration. Administering insulin should only be done after rehydration to avoid hypokalemia. The described symptoms and context suggest the patient may be experiencing diabetic ketoacidosis or severe hyperglycemia.
Step-by-step explanation:
The symptoms presented such as dry mouth, frequent urination, extreme thirst, and no recent fluid intake, combined with potentially omitted insulin doses, suggest the patient may be experiencing diabetic ketoacidosis (DKA) or severe hyperglycemia. The absence of insulin causes high blood glucose levels, leading to these symptoms. In DKA, the body starts breaking down fats, producing keto acids and possibly leading to a reduction in blood pH.
Before administering potassium or insulin, it is crucial to rehydrate the patient and stabilize their cardiovascular status. Therefore, the nurse's first action should be to begin infusion of 0.9% Sodium Chloride (0.9NS), which is used as an isotonic fluid to restore circulating volume and correct dehydration. Insulin should be administered only after ensuring the patient is properly rehydrated to avoid further complications with potassium levels, as insulin can drive potassium into cells and potentially lead to hypokalemia.
It is common for an aide to retrieve an IV bag with the specified concentration of KCl for a patient with hypokalemia, but this should be done after initial rehydration and careful assessment of the patient's potassium levels. A blood pressure of 70/45 mmHg indicates that the patient is likely in shock, possibly due to severe dehydration from DKA, which further underscores the need for prompt fluid resuscitation.